Fix blockseed for on_generated in mapgen env

src/emerge.cpp

@@ -692,7 +692,7 @@ void *EmergeThread::run()
 					"EmergeThread: Lua on_generated", SPT_AVG);
 
 				try {
-					m_script->on_generated(&bmdata);
+					m_script->on_generated(&bmdata, m_mapgen->blockseed);
 				} catch (const LuaError &e) {
 					m_server->setAsyncFatalError(e);
 					error = true;

src/emerge.h

@@ -50,6 +50,7 @@ class ModApiMapgen;
 // Structure containing inputs/outputs for chunk generation
 struct BlockMakeData {
 	MMVManip *vmanip = nullptr;
+	// Global map seed
 	u64 seed = 0;
 	v3s16 blockpos_min;
 	v3s16 blockpos_max;

src/mapgen/mapgen.h

@@ -167,6 +167,7 @@ private:
 */
 class Mapgen {
 public:
+	// Seed used for noises (truncated from the map seed)
 	s32 seed = 0;
 	int water_level = 0;
 	int mapgen_limit = 0;
@@ -180,6 +181,7 @@ public:
 	EmergeParams *m_emerge = nullptr;
 	const NodeDefManager *ndef = nullptr;
 
+	// Chunk-specific seed used to place ores and decorations
 	u32 blockseed;
 	s16 *heightmap = nullptr;
 	biome_t *biomemap = nullptr;

src/script/cpp_api/s_mapgen.cpp

@@ -45,7 +45,7 @@ void ScriptApiMapgen::on_shutdown()
 	runCallbacks(0, RUN_CALLBACKS_MODE_FIRST);
 }
 
-void ScriptApiMapgen::on_generated(BlockMakeData *bmdata)
+void ScriptApiMapgen::on_generated(BlockMakeData *bmdata, u32 seed)
 {
 	SCRIPTAPI_PRECHECKHEADER
 
@@ -66,7 +66,7 @@ void ScriptApiMapgen::on_generated(BlockMakeData *bmdata)
 	lua_pushvalue(L, vmanip);
 	push_v3s16(L, minp);
 	push_v3s16(L, maxp);
-	lua_pushnumber(L, bmdata->seed);
+	lua_pushnumber(L, seed);
 	runCallbacks(4, RUN_CALLBACKS_MODE_FIRST);
 	lua_pop(L, 1); // return val
 

src/script/cpp_api/s_mapgen.h

@@ -35,6 +35,6 @@ public:
 	void on_mods_loaded();
 	void on_shutdown();
 
-	// Called after generating a piece of map before writing it to the map
-	void on_generated(BlockMakeData *bmdata);
+	// Called after generating a piece of map, before writing it to the map
+	void on_generated(BlockMakeData *bmdata, u32 seed);
 };